• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1239-1242
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• 2006

본 논문에서는 IP 컨택센터에서 통화 처리 모의실험을 위한 VoIP 트래픽 발생기를 설계하고 구현한다. 구현된 트래픽 발생기(VoIPTG)는 H.323과 SIP 기반의 VoIP 콜 생성과 음성코덱(G.711, G.723.1등)을 사용하는 RTP 트래픽을 발생시킴으로써 다수의 대화자들이 음성 통화하는 상황을 모의실험을 할 수 있도록 해준다. VoIPTG를 이용하면 H.323 또는 SIP 세션 제어 프로토콜 선택, 사용자(call)수 변화, 시간 변화, 음성코덱의 선택 등 여러 가지 조합을 통해 다양한 모의실험 환경을 연출 할 수 있다. 이러한 트래픽 발생기는 IP 기반 컨택센터의 전반적인 기능 검사 및 성능평가를 위해 유용하게 사용될 수 있으며, 특히 IP 기반 녹취 시스템의 성능 평가를 위해서 필수적이다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.349-351
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• 2004

본 논문에서는 이더넷의 네트워크 진단과 분석을 위해 필수적인 트래픽 발생기를 IPv6주소체계를 지원하는 네트워크 환경을 고려하여 설계하고 구현한다. 인터넷주소의 고갈과 IPv4프로토콜의 비효율성을 개선하기 위해 IPv6프로토콜에 대한 연구가 활발하게 진행되고 있다. 또, 이더넷 트래픽은 패킷의 양과 프로토콜의 종류 그리고 패킷의 길이에 영향을 받는다. 본 연구에서 설계하고자 하는 트래픽 발생기는 이 세가지 항목을 조정하여 다양한 네트워크 트래픽을 발생하는 것을 목표로 한다. 설계된 트래픽 발생기는 허브, 라우터등의 네트워크 장비의 성능 명가와 패킷을 모니터링하는 소프트웨어들인 네트워크 진단 시스템과 침입탐지 시스템 등의 성능 평가 및 검증을 위해 사용될 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1503-1513
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• 1998

This paper is related to a performance analysis of B-NT system, which is essential compositional equipment of B-ISDN access network. A simulator enabling performance analysis according to the change of network configuration topology and the change of user traffic is developed in this study. The developed B-NT, system simulator consists of graphic user interface module, simulation program automatic generator module, and B-NT system model library module. As examples of the results of performance analysis using the simulator, end-to-end user cell transmission delay time, queueing delay time in each system, and cell loss rate in the head node switch are presented. The simulator developed in this paper can be utilized in determining the network topology of B-NT system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.1
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• pp.41-44
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• 2015

In cognitive radios, exponentially distributed idle period(EIP) is considered in this paper. In the EIP case, durations of idle periods are be limited and varied by primary traffic arrivals. Accordingly, we first analyze the idle period utilization which can be achieved by the slotted ALOHA in cognitive radio communications. The idle period utilization is a newly defined performance metric to measure the transmission performance of the secondary network as effective time durations utilized for successful secondary transmissions in an idle period. Then, the idle period utilization is maximized through controlling the data transmission time. All technical processes are mathematically analyzed and expressed as closed form solutions.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.25-28
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• 2001

This paper introduce a millimeter-wave radar system. As Fig 1 shows, This system consists of millimeter-wave radar front-end and digital signal processing parts through receive waves regarding up-coming obstacles. The system works as follow process; (1) Generate regular tripodal waves using the FMCW pulse generator (2) Transmit/Receive waves regarding up-coming obstacles (3) Analog filtering (4) FIFO memory interface (5) FFT(Fast Fourier Transform) (6) Calculation of distance / speed between cars (7) Object display and calibration. We have progress to solve the problem like as increase of traffic accidents causing damage and injuries due to the increased number of motor vehicles and long distance driving, and Need for a device to help drivers who are in trouble due to bad weather conditions. We are expect to Take the lead as a core technology in the ITS industry and to develop circuit and signal processing technologies related to millimeter-wave bandwidth.

• New & Renewable Energy
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• v.4 no.4
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• pp.30-36
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• 2008

The possibility of whether the induced wind from a vehicle traveling on highway can be used in wind power generation has been verified through computational flow analysis. The bus which is presumed to accompany relatively strong and wide range of induced wind compared to passenger vehicles because of its wide frontal area has been set as the subject of research. In order to ensure the reliability of research, the flow analysis surrounding the bus on a flat road where median strip is not installed has been compared with a preceding research while the validity of grid system and interpretation method used in this research have been assured by a qualitative method. In case of the median strip type wind power generator system, because it has been verified that a strong streamwise wind speed (5 m/s) is derived from the contraction effect of flow passage between the bus and the median strip while maintaining a relatively consistent upwind wind speed (1.4 m/s) in vertical direction in the wake area after the bus passes by although the change of wind speed is intense, it was decided as having some possibility of wind power generation. In case of the traffic sign panel type wind power generator system installed at the upper top of highway, because the wind speed of 2 m/s level has been derived for a limited time only at a section equal to the length of the bus and a faint induced wind speed less than 0.5 m/s was shown at other regions, it was decided as having almost no possibility of wind power generation.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.80-83
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• 2008

As SOC (Social Overhead Capital) has been expanded, the highway road construction has been accelerated and city road system has been more complicated. So, long road tunnels have been increased and traffic flow rate also has been raised. Accordingly, the exhausting gas of vehicle cars seriously deteriorates the tunnel inside air quality and driving view. In order to improve tunnel inside air quality, we may need to introduce a compulsory ventilation system as well as natural ventilation mechanism. The natural ventilation mechanism is enough for short tunnels, meanwhile longer tunnels require a specific compulsory ventilation facility. Many foreign countries already have been devoting on development of effective tunnel ventilation system and especially, some European nations and Japan have already applied their developed tunnel ventilation system for longer road tunnels. More recently, as the quality of life improved, our concerns about safety of driving and better driving environment have been increased. In order to obtain clearer and longer driving view, we are more interested in EP tunnel ventilation system in order to remove floating contaminants and automobile exhaust gas. Evan though it's been a long time since many European countries and Japan applied more economical and environment-friendly tunnel ventilation system with their self-developed Electrostatic Precipitator, we are still dependant on imported system from foreign nations. Therefore, we need to develop our unique technical know-how for optimum design tools through validity investigation and continuous possibility examination, eventually in order to localize the tunnel ventilation system technology. In this project, we will manufacture test-run products to examine the performance of system in order to develop main parts of tunnel ventilation system such as electrostatic precipitator, high voltage power generator, water treatment system, etc.

• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.11-18
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• 2012

Deep packet inspection which perform pattern matching to search for malicious patterns in the packet is most computationally intensive task. Hardware-based pattern matching is required for real-time packet inspection in high-speed network. In this paper, we have designed and implemented network intrusion detection hardware as a Microblaze-based SoC using Virtex-6 FPGA, which capture the network input packet, perform hardware-based pattern matching for patterns in the Snort rule, and provide the matching result to the software. We verify the operation of the implemented system using traffic generator and real network traffic. The implemented hardware can be used in network intrusion detection system operated in wire-speed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1524-1531
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• 2004

This study analyzes a load balancing technique using Round Robin Algorithm. The study uses two software packages (Packet Capture and Round Robin Test Package) to check packet volume from Virtual Network structure (data generator, virtual server, Server1,2,3), and finds out traffic distribution toward Server1,2 and 3. The functions of implemented Round Robin Load Balancing Monitoring System include round robin testing, system monitoring, and graphical indication of data transmission and packet volume. As the result of the study shows, Round Robin Algorithm allows servers to ensure definite traffic distribution, unless incoming data loads differ much. Although error levels are high in some cases, they were eventually alleviated by repeated tests for a long period of time.

• The KIPS Transactions:PartC
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• v.10C no.7
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• pp.899-914
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• 2003

It is generally accepted that self-similar (or fractal) processes may provide better models for teletraffic in modern telecommunication networks than Poisson Processes. If this is not taken into account, it can lead to inaccurate conclusions about performance of telecommunication networks. Thus, an important requirement for conducting simulation studies of telecommunication networks is the ability to generate long synthetic stochastic self-similar sequences. Three generators of pseudo-random self-similar sequences, based on the FFT〔20〕, RMD〔12〕 and SRA methods〔5, 10〕, are compared and analysed in this paper. Properties of these generators were experimentally studied in the sense of their statistical accuracy and times required to produce sequences of a given (long) length. While all three generators show similar levels of accuracy of the output data (in the sense of relative accuracy of the Horst parameter), the RMD- and SRA-based generators appear to be much faster than the generator based on FFT. Our results also show that a robust method for comparative studies of self-similarity in pseudo-random sequences is needed.